Cannot set properties of undefined (setting 'Rectange')

[NicolasEhrhard]

Hi, when i add your package from npm to my angular app, i've got this error.

Uncaught TypeError: Cannot set properties of undefined (setting 'Rectangle')
at getTreemap (index.js:89:3)

If i use it on jsfiddle for exemple, directly with the bundle.min.js file, it works.

Thanks.